So I was considering buying that robot kit I posted about the other day. "Considering" because it's like a thousand bucks, and I'm not sure it's a thousand bucks worth of entertainment. Two fifty, surely, but a grand? But then I did some more poking around and hit the part of the assembly instructions that go, "Now download flargle.exe, connect to COM1 and diddle the flibbidy registers". So I emailed them, asking, "Really?" Turns out? "Yeah." Apparently the entire hobbyist-robotics industry assumes a substrate of Windows. What the hell guys.

So, now this is sounding less like "a fun 3d jigsaw puzzle to assemble! And when you're done, it walks!" and more like, "figure out how to get your Mac to run Windows (which it does not have) to talk to a serial port (which it does not have) to run UI software written by a hardware guy". Aside from the part of this that is clearly against Policy, this also sounds like a heaping dollop of Not Fun. In fact, my back-of-the-envelope calculations suggest that the entertainment value of this toy decreases by about $25 per minute spent screwing around with the serial port. It's hard to assign a value to time spent in Windows, because I'd have to be pretty heavily sedated to even consider that, so I imagine my sense of time would be skewed. Still, I think it's in the red before I even open the box.

Also! Apparently the robot's software is written in Excel! No, seriously.

42 Responses:

Shame about the cost. I'm betting it's mostly the servos, let's see... 12 high-torque servos @ $36/ea + 6 regular servos @ $17 ea = $550! I never have figured out why servos are so expensive. It can't be the electronics, can it (how hard is it to decode PWM)? I doubt it's the motors or gear train. Are rotary encoders really that expensive?

Well, it depends on what size, torque, speed, and accuracy/quality. The primary type I've used are $3 to $3.50 (HXT-900 or EM 9g, nylon gears), or less in bulk. Worth noting that these are analog servos, with all the signal processing done by a separate unit, the ESC (electronic speed control). HXT brand gets good reviews on their site & in other forums in the small electric plane category.

Let's hope the Lynxmotion guys read jwz's LJ, cuz it looks like they could take at least a couple hundred dollars off the cost of the hexapod with servos from there. I'm sure they're even cheaper (and shipping costs even less) per unit if you buy in quantity.

Lots of AI guys have given up on robotics and are choosing to work with virtual worlds because with robotics you spend all your time working on getting the hardware working, doing not-really-AI stuff like vision processing, instead of actually working on cognition.

Having said that, the project I work on (OpenCog) is planned to be hooked up to some Chinese consumer bot with FPGA by people at Xiamen university. The people funding these projects seem to like having real world things to interact with.

I've always argued that the fiddly real world stuff is what makes it interesting -- if AI can't deal with that, it simply isn't done yet. In a virtual world you could all too easily miss seeing just how hard the SLAM problem is, which would be a shame because the modern solutions are really quite impressive.

I poked around quite a bit after you first posted the link, and found that there was a USB connection option available, which would work fine with VMware & Windows, but yeah, when I realized that the damned things run on BASIC (Basic Stamp? Really?) and one of the primary means for interacting with it was via Excel...

*shudder*

What really puzzles me is that the server controller board was like $50, and the Basic Stamp 2 controller something like $30. Are the servos, batteries, and aluminum frame bits really worth $920? Thinking more about it, I think the majority of the cost really is in the servos, since you're using 18 of them, that's about $51/servo assuming there are no other costs in the kit that I'm missing. How much do servos cost on their own?

The majority of the cost isn't in any of the parts, it's in paying for the development and the assembly line setup. Small market ==> small number of sales ==> comparatively large amount of the back end development cost embedded in each sale price.

jwz: that serial port shit is EVERYWHERE in niche hardware. A lot, a lot, A FREAKING LOT of hardware guys just haven't ever learned anything else since they went to school sometime in the 70s. I work with scientists that need to do a lot of sensing (remote and otherwise) and EVERY. FREAKING. THING. Is serial. Usually not even with Windows control apps, with MS-DOS control apps.

Serial ports are dirt simple, cheap, and pretty much work. I'd rather spend twenty minutes futzing with baud rates or gender changers than two days futzing with some custom USB driver. (Though, most of the time in products of this size, if it uses USB that's just because they put a USB->UART chip on the board where the DE9 used to be.)

... except that almost no modern computers HAVE serial ports anymore, meaning that you've STILL got to futz with USB and fake serial communication as emulated on the other end of a USB device anyway. Fail.

Also fail: the idea that a serial controller is, these days, any cheaper than a USB controller. (The one thing I will grant you is that serial connections are somewhat more robust to the elements, in extreme environments, since they don't have the 5V rail that USB does. Then again, if that's the concern, why the heck aren't you using bluetooth to avoid the issue of corroded interfaces entirely...?)

Sorry, I'm just not a fan of niche industry hanging onto ancient standards WELL past their obsolescence. I don't like it in sensors and instruments, and I also don't like it in (for instance) the legions of CPA industry apps I still run across that are written for Windows 3.11.

Servos add up fast, as do custom-cut aluminum frame bits and a zillion fiddly little mechanical pieces. That said, $600-$700 seems like a more reasonable price for this kit to me. You're paying for having all the integration and testing done for you already, I guess.

Looking at the hexapod kit, I bet you could easily toss out the BASIC thingy and its carrier board (or buy it alacarte or this or etc) and just talk to the SSC-32 directly. Put a gumstix or an old pda on it to do all the motion computation and talk to it with wifi. Spend a year writing kinematics code.

I didn't mean to sound like Cap'n Obnoxious saying it... sorry if I did.

As of the last time I looked, it was difficult to find a usb serial adapter that is compatible with Mac OS X, though. A lot of them work with Linux, but no Mac drivers exist. That's why I recommended the Prolific chip equipped USB adapters. Most other chips are stuck in Windows only land.

Given the rest of the project, I'd be stunned if writing a more portable simple interface to the hardware would be beyond your capabilities, even to port some of the logic from Excel. Not that I'd suggest you do this for free. Maybe in exchange for half a dozen or so kits.

.. just the ones that drank the redmond koolaid. Plenty of other hackers out there - there's bots and such for sale at http://makershed.com, for instance, which owe nothing to billg. Plenty of people have done bots based on arduino stuff, too.

So I think you just stumbled across (stepped in?) the wrong part of the hobbyist-robotics crowd. Don't give up hope, if that's what you're interested in.